It's always a bit stressful when you see red and blue lights in your rearview mirror. But North Texas residents have extra cause for concern due to a recent rash of police impersonations.

Three separate incidents involving fake police officers in Dallas, Carrollton and Denton have yet to be solved — or even connected. Suspect descriptions indicate there are at least two different suspects at large: a bald, light-skinned black male and a white male with short gray hair. Both are using vehicles equipped with flashing lights.

The latest incident occurred around 2 am on December 13. A man posing as a police officer pulled over a woman on Airport Road in Denton.

According to police, the woman was retrieving her license and registration when the fake officer reached into her car and tried to attack her. The woman fought back and the police impersonator, who was dressed in dark clothing, ran off.

The man's vehicle appeared to have red and blue lights, though the area was so poorly lit the woman was not able to give police any other description of the car or the suspect. Ryan Grelle, public information officer with the Denton Police Department, says his office has contacted Carrollton police to try to determine if the latest suspect is the same person who sexually assaulted a woman last month.

On November 21, a dark vehicle believed to be a Ford Crown Victoria flashed blue lights and pulled over a woman driving on Interstate 35 East in Carrollton, between Valley View Lane and Valwood Parkway. A man dressed as a police officer replete with a gold badge and name tag told the woman she was being arrested on warrants and proceeded to handcuff her.

Once placed in the backseat of the four-door sedan, the police impersonator sexually assaulted the woman. Carrollton police released a sketch of the suspect on November 27. He is described as a white male in his 30s or 40s with a medium build and short facial hair. He is between 5-foot-5 and 5-foot-8 with short gray hair.

Another police impersonator recently conducted a traffic-stop-turned-robbery in Dallas. Around 10 am on December 6, a man driving an SUV in the 2600 block of Highland Road was pulled over by a black Dodge Charger with flashing red and blue lights. The fake police officer took the man's driver's license and insurance card before pointing a black revolver into the car and stealing the man's wallet. The suspect in that case is described as a 5-foot-10-inch, bald, light-skinned black male in his mid-20s.

Meanwhile, fake police officers in Houston are knocking down doors and invading homes. To date, there are three unsolved robberies involving men posing as police officers to gain entry into homes. Once inside, the suspects assault the occupants and ransack their place.

If you have any reason to question the identity of a police officer, you are encouraged to call 911 and drive to a public, well-lit area before pulling over. The police car should be clearly marked and officers should have proper identification displayed at all times.